It is often necessary to supply capacitive loads, such as an electrical amplifier, a Geiger-Muller tube, or an ultrasound transducer, with a high voltage supply. For certain specific applications, it is also necessary to tie the voltage level applied to the capacitive load, and possibly the profile of the applied voltage, to an input signal, which can evolve very quickly.
Capacitive charge attack circuits which must be supplied with high voltage signals in a controlled manner generally combine quick all or nothing switching circuits with varying structures that require significant power. However, the known capacitive load supply circuits are ill-adapted to the execution of real time control of voltages of about one kilovolt with variation ranges of about a dozen or so microseconds. In most known circuits, weak output impedance can prove to be very dangerous for the user and auxiliary protection circuits must be included to guard against short circuits. Moreover, with traditional supply circuits, high voltage is automatically present on the output terminal, even when no load is connected, which is unsatisfactory for safety reasons.